1. Field of the Invention
This invention relates to an apparatus for the production of heated beverage and, in particular, although not necessarily solely, an apparatus for the production of coffee. Other brewable beverages could be made in the same apparatus.
2. Description of the Prior Art
Existing coffee makers utilize filters containing coffee grounds. Typically, heated water is passed through the apparatus to a point above the filter and allow to drip onto the coffee grounds and percolate through the coffee. The contact time between the heated water and the ground coffee is dependent on the rate at which the water can percolate. Such a rate is dependent on the conditions of both the ground coffee and the filter and may vary considerably through different operations or even during a single operation of the apparatus.
The variability of percolation times can be affected by the condition of the coffee and filter during percolation. At the outset of introduction of the heated water, both the coffee and filter are dry and become increasingly more saturated throughout the operation. This can affect the degree to which the heated water is able to extract the coffee essence from the grounds and lead to variability in the coffee produced at the start of the process compared with that in the middle or end of the process.
If such typical coffee makers are used to try and produce small amounts of coffee, it would be expected that the coffee filter would need to contain less coffee grounds, However, the reduction in quantity of coffee grounds also decreases the percolation time leading to variability in the judgment of the quantity of coffee required. Further, due to the reduction in contact time, the grounds are used less efficiently.
Another common feature of existing coffee apparatus is that the coffee produced is supplied to a container sitting on a heated element with the container not being sealed such that steam and aroma may escape. By allowing steam carried aromatic compounds to escape the container, the taste of the coffee may be affected.
The heated plate on which such containers typically sit is required to regularly reheat the coffee. By allowing steam to escape, such a heating element is required to do more work leading to less efficient power consumption to maintain a reasonable coffee temperature. Furthermore, by allowing steam to escape, there is a gradual boiling off of the water. The resultant coffee left in the container becomes increasingly stronger and more bitter as time passes. Furthermore, the increased use of the heating element to maintain the coffee temperature can lead to burning of the coffee significantly reducing the quality of the taste of the coffee from the container.